MDK-ARM Keil, MDK-ARM Datasheet - Page 82

• Manufacturer Part Number: MDK-ARM
• Description: KIT REALVIEW MCU DEVELOPMENT
• Manufacturer: Keil
• Type: Compiler and IDEr

Specifications of MDK-ARM

• For Use With/related Products: ARM MCUs
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

82
The Common Gateway Interface
The Common Gateway Interface (CGI) is a standard protocol for interfacing
application software to a TCP/IP server, typically a HTTP server. The CGI
protocol will take data from the TCP/IP server that has been entered from a client
and pass it to the application software in the form of an environment variable.
The CGI protocol also allows the application software to output data through the
TCP/IP server. In the case of a HTTP server, the data is output as dynamically
modified HTML.
To enable the CGI interface, we need to add a new C file from the RL-TCPnet
library to our project. This file is called
source directory
access the CGI interface must
have the extension .
than
The file
in the web server to the
application C code via a CGI.
Dynamic HTML
We have already discussed how to display static HTML pages. However, most
embedded web servers need to display the data held in the C application.
With the RL-TCPnet, this is done with a simple CGI scripting language that is
added to the HTML text. The CGI scripting language contains four basic
commands. These must be placed at the beginning of each HTML line within a
page that uses the CGI gateway. The commands are as follows:
Command
I
T
C
.
#
htm
HTTP_CGI.c
or
html
Description
Include a HTML file and output it to the browser.
The characters following this command are a line of HTML and should be output
to the browser.
This line of text is a command line and the CGI interface will be invoked.
A period ( . ) must be placed at the end of a CGI file.
A hash ( # ) character must be placed before a comment.
as shown below.
C:\KEIL\ARM\RL\TCPNET\SRC
links events
cgi
rather
HTTP_CGI.C
. In addition, any HTML file that will
Chapter 4. RL-TCPnet Introduction
and is stored in the TCPnet